Due to air pollution regulations which are highly stringent concerning the release of H.sub.2 S to the atmosphere, it is conventional to convert H.sub.2 S in waste gas streams to SO.sub.2 prior to discharge to the atmosphere. Usually, this is accomplished thermally, that is, the gas stream is blended with sufficient of a fuel gas to produce a combustible mixture, which, when combusted, produces a flue gas containing SO.sub.2 and essentially no H.sub.2 S.
As an alternative to thermal combustion, it is also known to catalytically incinerate H.sub.2 S to SO.sub.2 by passing H.sub.2 S and O.sub.2 through a bed of catalyst particles at an elevated temperature and at a space velocity sufficient to oxidize the H.sub.2 S to SO.sub.2. For example, in United Kingdom Pat. No. 733,004, published Jan. 23, 1953, it is taught that a catalyst composed of 5-10 wt.% V.sub.2 O.sub.5 on alumina is effective for reducing H.sub.2 S concentrations in Claus tail gas by conversion to SO.sub.2. But such a catalyst is necessarily susceptible to sulfation, a form of catalyst deactivation wherein the alumina support is attacked in environments containing SO.sub.2 plus O.sub.2 or SO.sub.3 or both, resulting in loss of crushing strength, surface area, and of most importance, activity.
Accordingly, it is a primary object of the invention to provide a catalyst comprising an aluminum-containing support that is highly active for incinerating H.sub.2 S but is resistant to sulfation. It is another object to provide a catalyst for selectively oxidizing H.sub.2 S to SO.sub.2 in the presence of such gases as H.sub.2, CO, NH.sub.3, and light hydrocarbons (herein defined as those saturated hydrocarbon gases containing no more than six carbon atoms). Other objects and advantages will be apparent to those skilled in the art in view of the following disclosure and claims.